0.05). The dose of GnRH (10mg vs. 20mg) and the progesterone concentration did not interfere in ovulation in the beginning of the treatment (P>0.05). Animals that ovulated (n = 20) after the first GnRH injection presented larger follicular diameter (P <0.01) that those that no ovulated (n=13). In PGF2alpha injection, the follicular diameter was 10.3 ± 2.0mm. The Group 1 presented larger follicular diameter than the Group 2 (P <0.01). Animals that ovulated after the first GnRH injection (n=20) presented higher progesterone concentrations in the day of PGF2alpha injection (P <0.05). It was observed that 78,80% female buffaloes treated presented synchronized ovulation and, the first dose of GnRH did not interfere in the efficiency of the protocol (P>0.05). In Experiment 2, it was observed conception rate of 45.40% (n = 1053). Animals synchronized during the favorable reproductive season presented better conception rate than the unfavorable season (48.80% vs. 6.90%; P <0.05). The conception rate was influenced by body condition score of the animals and parity during the favorable reproductive season (P <0.05). The conception rates did not differ according to the year (1998 and 1999) of artificial inseminations and the postpartum period in the beginning of the treatment (P>0.05). In summary, the Experiments indicated that the use of synchronization of the ovulation for fixed timed insemination, during the favorable reproductive season, presents satisfactory results in buffalo and could still be better when used multiparous buffaloes with good body conditon score in the beginning of the treatment.]]>

No abstract

Automated monitoring devices (AMD) have become more affordable, and consequently more popular among dairy producers. We hypothesized that the addition of AMD-generated health alerts to a health-screening program improves survival, milk production, and reproductive success. In addition, we hypothesized that cows diagnosed with clinical disease that have AMD alerts are at greater risk of culling, lower milk production, and decreased risk of pregnancy than cows without AMD alerts. Holstein cows (nulliparous = 282, parous = 328) were enrolled at −60 ± 3 d (d 0 = calving), when they were fitted with an AMD and assigned randomly to 1 of 2 health-screening strategies: (1) control: AMD alerts not provided to farm personnel; and (2) automated device: AMD alerts provided to farm personnel. Twice daily, study personnel determined which cows had AMD alerts (health index ≤79, rumination <200 min/d, or difference between current rumination and the average of the 3 preceding days <0) and provided the information to farm personnel. Farm personnel examined cows at 3, 5, and 9 d in milk (DIM) and when daily milk yield decreased ≥25% on consecutive days. We detected no differences between health-screening strategies regarding morbidity (control = 49.7 ± 3.3%, automated device = 52.8 ± 3.2%), but the interaction between health-screening strategy and parity tended to be associated with the number of clinical diseases per cow (primiparous: control = 0.46 ± 0.06, automated device = 0.65 ± 0.07 cases/cow; multiparous: 0.88 ± 0.08, automated device = 0.86 ± 0.08 cases/cow). Cows enrolled in the automated device strategy were more likely to be treated with supportive therapy (64.4 ± 3.1 vs. 55.0 ± 3.2%), whereas primiparous cows in the automated device strategy were more likely to be treated with anti-inflammatory drugs than those in the control strategy (41.6 ± 4.7 vs. 23.8 ± 4.0%). Health-screening strategy did not affect survival or total milk yield up to 22 wk postpartum, but cows in the automated device strategy had reduced risk of pregnancy after the first 2 services (54.5 ± 3.0 vs. 46.2 ± 3.2%). Cows diagnosed with a clinical disease without AMD alerts had reduced risk of removal from the herd by 150 DIM (5.7 ± 2.0 vs. 19.0 ± 3.3%), greater risk of pregnancy after the first 2 services (49.6 ± 4.5 vs. 33.6 ± 3.9%), and greater milk by 22 wk postpartum (6.7 ± 0.2 vs. 5.3 ± 0.2 × 10 3 kg) than cows diagnosed with a clinical disease that had an AMD alert. Adding AMD-generated health alerts to the health screening of postpartum cows in a herd with an existing screening program did not improve survival, milk yield, or reproductive success. In addition, AMD alerts in cows diagnosed with a clinical disease may be indicative of the future success of such cows.

0.05). Conception rates were 48.00% (60/125) and 40.90% (56/137) in Group 1 and Control Group, respectively. It was observed that 88.60% (n = 35) of the buffaloes in Group 1 and 90.00% (n = 30) in Control Group presented luteolysis 48 hours after the PGF2alpha injection (P>0.05). In summary, present data show that both treatments result in acceptable conception rates. Therefore, the recommended dose of PGF2alpha can be reduced in 50.00% in the synchronization of ovulation protocol for fixed-time artificial insemination in buffalo.]]>

A Deus pela minha vida primeiramente, e é a quem devo toda a capacidade e condições para as realizações da minha vida.

O presente trabalho teve como objetivo identificar anticorpos anti-Neospora caninum em fêmeas bovinas da raça Nelore pelos métodos sorológicos de Imunoabsorbância Ligada a Enzima (ELISA) e Imunofluorescência Indireta (RIFI) e buscar associação entre a soropositividade e o histórico reprodutivo até 60 dias de gestação. Adicionalmente, nas amostras positivas foram realizados testes de ELISA-Avidez e ELISA para anticorpos anti-Toxoplama gondii. Para isto, foi constituído um banco de 375 amostras de soros, categorizados em três grupos, de acordo com o histórico reprodutivo de cada fêmea até os 60 dias após a Inseminação Artificial (I.A). Para a análise estatística utilizou-se o teste de Qui-Quadrado de Pearson (X²) e índice Kappa (k). Foram encontrados 8% (30/375) e 5,07% (19/375) de soros positivos para N. caninum pelo ELISA e RIFI, respectivamente, com o ELISA apresentando concordância alta com a RIFI (k = 0,67). A infecção encontrada nesse rebanho, revelado pelo ELISA-Avidez, foi considerada crônica. Nesse estudo, 9,08% das fêmeas soropositivas pela RIFI e 17,25% das fêmeas positivas pelo ELISA apresentaram algum problema reprodutivo. Entretanto, não foi encontrada associação significativa entre a soropositividade das vacas, com o retorno ao cio ou a ocorrência de aborto, observados até 60 dias de gestação (p>0,05). Não foi observado nenhum animal co-infectado por N. caninum e T. gondii.

Jo sé L á z a ro d a R O C H A 1; V alq u iria H yppolito BA R N A BE2; R en ato C a m p a n a ru t BA R N A BE1; Kd H offm ann V IA IH IRKIRA4; C laudio A lv aren g a de O L IV K IR A 4: José A ntonio V IS IN T IN 5Recebido para publicação em 04/02/93 Aprovado para publicação em 04/07/93

The negative effect of some diseases, such as bovine viral diarrhea (BVD), infectious bovine rhinotracheitis (IBR), and Leptospirosis, on bovine reproduction rates are well known. The uses of vaccines are considered to be an important tool available in order to control reproductive losses but their efficiency is still controversial. The aim of this study was to evaluate the effects of vaccination against BVD, IBR, and Leptospirosis to improve pregnancy rate in beef cattle submitted to fixed-timed AI (FTAI). Nelore cows (n = 1172) from 4 beef cattle farms in Brazil were randomly distributed in two experimental groups: Group 1 (treated, n = 584) received the first dose of the inactivated vaccines (Bioleptogen and Bioabortogen H, Biogénesis Bagó, Garín, Argentina) at the beginning of the FTAI protocol and the second dose on the pregnancy diagnostic 40 days later; Group 2 (control group, n = 588) received 0.9% saline solution. Serum samples from 3–5% of animals in each farm herd were collected to determinate IBR, BVD, and Leptospirosis challenges, by using ELISA protocol for BVD and IBR (Synbiotics BVD p80 ab monoblocking test and Synbiotics BoHV-1 gB monoblocking test, respectively; Synbiotics Corp., Kansas City, MO, USA); and microaglutination test for Leptospirosis. All animals were submitted to the FTAI protocol: D0 = intravaginal P4 device (Cronipress, Biogenesis Bagó) and application of 2 mg oestradiol benzoate (Bioestrogen, Biogénesis Bagó); Day 8 = intravaginal device removal + 0.5 mg oestradiol cipionate (E.C.P, Zoetis Inc., Florham Park, NJ, USA) and 25 mg D-cloprostenol sodium (Croniben, Biogénesis Bagó) and FTAI after 48 h. Body condition scores (BCS) were measured on Day 0 and pregnancy diagnostic were performed on Day 40. Data were analysed by logistic regression using PROC LOGISTIC procedure of the SAS software (SAS 9.3, SAS Institute, Inc., Cary, NC, USA) as well as the significant differences between the factors was analysed to nonparametric statistical frequency (chi-square test; PROC FREQ). Pregnancy rates on day 40 were greater (P < 0.0001) in Group 1 (58.21%; 340/584) compared to Group 2 (44.73%; 263/588). Effect in BCS by pregnancy rates was observed (P = 0.0165) among animals with higher compared to lower BCS (61.40% v. 47.98%, respectively). Results from BVD, IBR and Leptospirosis prevalence were respectively (78.26%; 95.65%, and 10.20%), demonstrating that all herds were challenger for the 3 agents and a positive correlation with pregnancy rates (P < 0.001) in vaccinated group. In conclusion, vaccination with Bioabortogen H and Bioleptogen contributed to increase pregnancy rates in beef cattle submitted to FTAI; and the positive correlation between high prevalence of BVD, IBR, and leptospirosis, and an increased pregnancy rate by 13.48% can be due to fewer losses caused by the vaccination protection up to Day 40.